Blender - How to taper a bevel?
I think I found an answer whilst playing around after reading @mma78 answer.
I can snap the 3D cursor to the bottom vertex and then bevel the edge. I can then set the Pivot point to 3D Cursor and scale the bottom vertices back in. This way the bottom is tapered while keeping the shape of the base unchanged.
While this works, it is not very efficient as I would have to repeat the process for the other 3 corners. If anyone knows of a quicker way to go about this that would be great.
Still, I hope this helps someone.